Refined karst feature and fault identification through integrated wave field separation and imaging of Diffraction energy

In this abstract, a case study from offshore Indonesia is showcased with examples emphasizing integrated wave field separation methods with the objective of diffraction imaging towards refined karst feature and fault identification. For imaging optimally all diffraction energy, pre-migration and post-migration methods have been integrated. The dataset and examples in this abstract are in a complex geological setting in a very shallow water environment, with a subsurface that is characterized by large carbonate pinnacles containing large amount of karst features with thinning and thickening carbonate layers. For the purpose of refined imaging of diffraction energy only, the total wave field has been separated into specular reflections and diffractions prior to migration and these have been integrated with existing post-migration wave field separation methods. Both the pre-migration and post-migration wave field separation methods have their advantages and disadvantages and is discussed later in this abstract. Diffraction energy, in general is much lower in amplitude than the specular reflections and separately imaging these, unveils higher resolution small scale geological features such as karst features and faults complementing the total wave field PSDM data. With existing industry available methods applying wave field separation in either pre-migration or post-migration stage, limitations have been observed, and therefore we propose in this abstract to integrate both methods and take advantage of the improvements showcased with examples throughout the abstract.

Sound field separation of multiple coherent sound sources with single measurement surface

Sound field separation based on near-field acoustical holography has been developed worldwide, but with the increase in the number of sound sources, traditional measurement methods and calculation methods will generate more workload. To reduce the number of measuring points and save calculation time, the sound field separation of multiple coherent sources with a single measurement surface is proposed. On the basis of separating two coherent sources with this method, the separation formula of more sources based on an equivalent source method is given. Through numerical simulation, the effects of the number of holographic surface measuring points, measuring distance, array shape, and equivalent source number on the calculation accuracy of the sound field separation were compared at different frequencies. The correctness and effectiveness of the sound field separation method with a single surface are verified by actual experiments.

The Mechanical Harvesting of Hemp Using In-Field Stand-Retting: A Simpler Approach Converted to the Production of Fibers for Industrial Use

The mechanical harvesting of hemp is a key step toward a profitable use of the product. Various fractions (fiber, seeds, residual biomass) may be recovered, and their correct management is fundamental for complying with the requirements of processors/end users. In the light of the renewed interest for its industrial use (panels and insulators), this work proposes the use of modified commercial machines to implement a field separation of the fibrous fraction of stand-retted hemp, a practice that would be profitable if realized with the systems adopted for textile use. The present work was conducted to test the efficiency of harvesting partially macerated plants by using a modified self-propelled forage harvester (SPFH). In Northern Italy, a hemp crop was stand-retted for four months. Then, an SPFH—with rotor knives reduced in number from 24 to 12—was used. Stand-retting made it possible to separate cortical fibers from the inner stem cylinder during harvesting; 53.3% of the material (fibers and shives) was separated automatically by the SPFH together with the chopped bast fiber, while the remaining 46.7% was separated on exiting the launch tube. More than 50% of the fibers were shorter than 5 cm in length, while almost 15% were longer than 10 cm. The SPFH had an effective operating speed of 3.48 km h−1, and no clogging occurred during the test. Therefore, the combination of stand-retting with harvesting using a modified SPFH could be helpful in obtaining an early separation of fibers from shives, thus facilitating the product treatment during its subsequent processing, e.g., by enhancing the defibration.

Incorporating Field Effects Into Functional Product-System Architecting Methods

System architecture and modularity decisions are inherent to preliminary concept design. Prior modularity research has considered minimizing interactions between modules and increasing the commonality among modular product variants. Effective approaches include function structure partitioning guidelines, affinity analysis, or matrix clustering algorithms. We consider here designs with field constraints, such as situations when elements cannot be placed in certain regions such as a high-temperature field, a high-pressure field, a high magnetic field, etc. which place constraints on modularity choices. Practical design guidelines are developed here for modularity considering field constraints. Two types of guidelines are proposed, field separation and concept generation. The field separation guidelines propose zonal boundaries within which system modules need be confined. The concept generation guidelines propose how to violate the field constraints through new concepts. Moving functionality from one side of a field boundary to the other is nontrivial and involves new concept generation for the modules to function at the higher or lower field values. The guidelines are defined and illustrated via multiple common examples as well as two extended case studies. We demonstrate the approach using field boundaries on an electric motor controller and on a medical contrast injector, and also use of fields to generated novel concepts. The guidelines support for modularity concept and embodiment decisions.